Look at pictures of quilts that attract your attention.
Determine the main colors in those quilts.
Notice closely what colors are used that might surprise you.
Then notice how much of each color the quilter used.
Did she change the value of those colors (using lights, mediums and darks)?
Google images of fresh flower, or wild flowers, or specific flowers.
Go through the same process as you find flowers that attract your attention.
In a red flower, are there several values of red? Does it contain pink? Light? Dark? How about peach or even orange in it?
Train your eye by spending time doing this a bit every day, or week, until you begin to feel comfortable with colors that work well together. They are all around you! So much in nature is inspirational. Even when the trees bud in spring, you will notice there are many, many values of green.....and even red/pink/rust/burgundy, all at the same time!
You don't have to carry any tool around with you, just your eyes. And they are always with you!
Jan in VA